As a participating institution in the Primary Breast Cancer Therapy Group (NSABP), we are contributing data from patients entered into Protocol No. 4 of the group, which is a protocol to evaluate the relative efficacy of radical mastectomy, total mastectomy with radiation and total mastectomy alone in patients with clinically negative axillary nodes. A comparison between radical mastectomy and total mastectomy with radiation is also made in those with positive axillary nodes. The present application seeks funding (a) to permit continued patient accurual in on-going protocols, (b) to continue follow-up of patients entered into protocols which have terminated, and (c) to collect appropriate biological material and information relevant to such protocols. The new protocols are: (1) No. 6: A trial to compare the worth of segmental mastectomy with and without breast radiation with total mastectomy plus axillary dissection. All patients will undergo axillary dissection and those with histologically positive axillary nodes will receive adjuvant chemotherapy. (2) No. 8: A trial to compare the worth of three-drug chemotherapy (L-PAM, 5-FU and methotrexate) with 2-drug chemotherapy (L-PAM and 5-FU). (3) No. 9: A trial to determine whether the anti-estrogen Tamoxifen when combined with chemotherapy improves the results obtained with chemotherapy alone. (4) No. 10: A trial to compare the value of the immunopotentiator C. parvum combined with chemotherapy vs. chemotherapy alone. (5) No. 11: A trial to evaluate various treatment modalities in the management of patients with Clinical Stage III breast cancer. In addition, the NSABP membership has decided, because of its unique membership, to implement adjuvant protocols for primary colo-rectal carcinoma. The group has the same capability to accomplish this as it has done for breast cancer. This institution may participate in such protocols. Finally, an aim of this proposal is to enhance the multidisciplinary approach of this institution in clinical trials.